CN110140312B - Method for retransmitting data by terminal in wireless communication system and communication apparatus using the same - Google Patents

Abstract

A method for a terminal to retransmit data in a wireless communication system and a communication apparatus using the same are provided. The method comprises the following steps: receiving Downlink Control Information (DCI) from a network; and retransmitting the data based on the DCI, wherein the DCI includes an acknowledgement/negative acknowledgement (ACK/NACK) field.

Description

Method for retransmitting data by terminal in wireless communication system and communication apparatus using the same

Technical Field

The present invention relates to wireless communication, and more particularly, to a method of retransmitting data by a terminal in a wireless communication system, and a communication apparatus using the same.

Background

As more and more communication devices utilize greater communication capacity, there is a need to improve mobile broadband communications over existing radio access technologies. In addition, large-scale Machine Type Communication (MTC) that provides various services by connecting many devices and objects is one of major issues to be considered in next-generation communication.

Further, communication system design is being discussed that considers reliability/delay sensitive services/UEs. The introduction of next generation radio access technologies considering enhanced mobile broadband communication (eMBB), large-scale mtc (mtc), ultra-reliable and low-latency communication (URLLC) is discussed. For convenience, this new technology may be referred to as a new radio access technology (new RAT or NR) in this disclosure.

Meanwhile, data retransmission through a hybrid automatic repeat request (HARQ) process may also be performed in the NR. However, in NR, by defining a channel spread in units of a system bandwidth, a more efficient use method using consumed symbols is being discussed. And, therefore, discussion is also being made regarding a method of performing a HARQ process without employing a Physical HARQ Indicator Channel (PHICH) in the related art LTE.

Accordingly, the present invention uses Downlink Control Information (DCI) as a retransmission indicator so that a method of retransmitting (or retransmitting) data performed by a terminal (or User Equipment (UE)) is provided.

Disclosure of Invention

Technical purpose

A technical object to be achieved by the present invention is to provide a method for a terminal to retransmit data in a wireless communication system, and a communication apparatus using the same.

Technical scheme

According to an embodiment of the present invention, there is provided a method of a User Equipment (UE) retransmitting data in a wireless communication system. The method includes receiving Downlink Control Information (DCI) from a network, and retransmitting data based on the DCI, wherein the DCI includes an acknowledgement/negative acknowledgement (ACK/NACK) field.

Here, the retransmission may be a non-adaptive retransmission (non-adaptive retransmission).

Here, the DCI may indicate retransmission per hybrid automatic repeat request process identifier (HARQ process ID).

Here, the DCI may indicate retransmission per subframe within a subframe window.

Here, in case of defining a counter field of a notification scheduling index within an Uplink (UL) grant, DCI may signal a last counter value.

Here, the counter value may be initialized when DCI is received.

Here, in the case where a polling on/off field (polling on/off field) is defined within the UL grant, and when a polling on UL grant (polling on UL grant) is received in the nth subframe, the UL grant, which is an indication target of DCI received after the time point of the nth subframe, may correspond to an uplink grant received during the duration from the reception point of the most recent polling on uplink grant before the nth subframe to the (N-1) th subframe.

Here, the DCI may correspond to a UE-specific DCI or a DCI common to UEs.

Here, the DCI may include at least any one of a non-adaptive retransmission on/off field, a non-adaptive retransmission timing field, a Redundancy Version (RV) field, and an aperiodic Channel State Information (CSI) transmission request field.

Here, a Radio Network Temporary Identifier (RNTI) value related to the detection of the DCI may be independently signaled.

Here, the transmission-related parameters within the search space for the DCI may be predetermined.

Here, in the case where the UE receives both DCI for the same HARQ process ID and an uplink grant, retransmission may be performed according to the uplink grant.

Here, within the DCI, the HARQ ACK transmission timing field may be configured per HARQ process ID.

Here, within the DCI, an acknowledgement/negative Acknowledgement Resource Indicator (ARI) field may be configured per HARQ process ID.

According to another embodiment of the present invention, there is provided a communication apparatus including: a Radio Frequency (RF) unit that transmits and receives a radio signal; and a processor operatively connected to the RF unit. The processor is configured to receive Downlink Control Information (DCI) from a network and retransmit data based on the DCI, where the DCI includes an acknowledgement/negative acknowledgement (ACK/NACK) field.

The invention has the advantages of

According to the present invention, when a terminal (or User Equipment (UE)) performs data retransmission (or retransmits data), more efficient retransmission can be performed by using DCI as a retransmission indicator.

Drawings

Fig. 1 illustrates an example of a wireless communication system in accordance with some embodiments of the present disclosure.

Fig. 2 is a diagram illustrating an example of a radio protocol architecture for a user plane.

Fig. 3 is a diagram illustrating an example of a radio protocol architecture for the control plane.

Fig. 4 shows a structure of an uplink subframe in 3GPP LTE.

Fig. 5 shows a structure of a downlink subframe in 3GPP LTE.

Fig. 6 shows an example of a method of performing uplink HARQ in 3GPP LTE.

Fig. 7 illustrates a system structure of a next generation radio access network (NG-RAN) according to some embodiments of the present disclosure.

Fig. 8 illustrates an example of the functional division that can be implemented between NG-RAN and 5 GC.

Fig. 9 illustrates an example of a frame structure according to some embodiments of the present disclosure.

Fig. 10 shows an example of a multiplexing scheme within a single slot in NR.

Fig. 11 is a flowchart illustrating a method for retransmitting data of a UE according to an exemplary embodiment of the present invention.

Fig. 12 illustrates an overall view of a data retransmission method according to an exemplary embodiment of the present invention.

Fig. 13 illustrates an overall view of a data retransmission method according to an exemplary embodiment of the present invention.

Fig. 14 illustrates an overall view of a data retransmission method according to an exemplary embodiment of the present invention.

Fig. 15 shows a detailed example of applying the method of fig. 11.

Fig. 16 is a block diagram illustrating a communication device in which an embodiment of the invention is implemented.

Detailed Description

Fig. 1 shows a wireless communication system to which the present invention is applied. The wireless communication system may also be referred to as an evolved UMTS terrestrial radio Access network (E-UTRAN) or a Long Term Evolution (LTE)/LTE-A system.

The E-UTRAN includes at least one Base Station (BS)20, which provides a control plane and a user plane to a User Equipment (UE) 10. The UE 10 may be fixed or mobile and may be referred to by another term such as a Mobile Station (MS), a User Terminal (UT), a Subscriber Station (SS), a Mobile Terminal (MT), a wireless device, or the like. The BS 20 is typically a fixed station that communicates with the UE 10 and may be referred to by another terminology, such as an evolved node b (enb), a Base Transceiver System (BTS), an access point, or the like.

The BSs 20 are connected to each other by means of an X2 interface. The BS 20 is also connected to the Evolved Packet Core (EPC)30 by means of the S1 interface, more specifically to the Mobility Management Entity (MME) via the S1-MME, and to the serving gateway (S-GW) via the S1-U.

EPC 30 includes an MME, an S-GW, and a packet data network gateway (P-GW). The MME has access information of the UE or capability information of the UE, and such information is generally used for mobility management of the UE. The S-GW is a gateway with E-UTRAN as an endpoint. The P-GW is a gateway with the PDN as an end point.

Layers of a radio interface protocol between the UE and the network may be divided into a first layer (L1), a second layer (L2), and a third layer (L3) based on the lower three layers of an Open System Interconnection (OSI) model well known in the communication system. Among them, a Physical (PHY) layer belonging to a first layer provides an information transfer service by using a physical channel, and a Radio Resource Control (RRC) layer belonging to a third layer serves to control radio resources between the UE and the network. For this, the RRC layer exchanges RRC messages between the UE and the BS.

Fig. 2 is a diagram illustrating a radio protocol architecture for a user plane. Fig. 3 is a diagram illustrating a radio protocol architecture for the control plane. The user plane is a protocol stack for user data transmission. The control plane is a protocol stack for control signal transmission.

Referring to fig. 2 and 3, the PHY layer provides an information transfer service to an upper layer via a physical channel. The PHY layer is connected to a Medium Access Control (MAC) layer, which is an upper layer of the PHY layer, via a transport channel. Data is transferred between the MAC layer and the PHY layer via a transport channel. The transport channels are classified according to how data is transmitted over the radio interface and what characteristic data is transmitted.

Through the physical channel, data moves between different PHY layers, i.e., PHY layers of a transmitter and a receiver. The physical channel may be modulated according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme and use time and frequency as radio resources.

The functions of the MAC layer include mapping between logical channels and transport channels and multiplexing/demultiplexing of transport blocks provided through physical channels on transport channels of MAC Service Data Units (SDUs) belonging to the logical channels. The MAC layer provides a service to a Radio Link Control (RLC) layer through a logical channel.

The functions of the RLC layer include concatenation, segmentation, and reassembly of RLC SDUs. In order to ensure quality of service (QoS) of various types required by a Radio Bearer (RB), the RLC layer provides three types of operation modes: transparent Mode (TM), non-acknowledged mode (UM), and Acknowledged Mode (AM). The AM RLC provides error correction through automatic repeat request (ARQ).

The RRC layer is defined only in the control plane. The RRC layer is related to configuration, reconfiguration, and release of radio bearers and is responsible for control for logical channels, transport channels, and physical channels. The RB means a logical path provided through first (PHY) and second (MAC, RLC, and PDCP) layers in order to transfer data between the UE and the network.

Functions of the Packet Data Convergence Protocol (PDCP) on the user plane include transfer and header compression of user data, and ciphering. The functions of the PDCP layer on the control plane include transport and ciphering/integrity protection of control plane data.

What kind of RB is configured means a process of defining characteristics of a radio protocol layer and a channel in order to provide a specific service and configuring each detailed parameter and operation method. The RB can be divided into two types of signaling RB (srb) and data RB (drb). The SRB is used as a tunnel through which RRC messages are transmitted on the control plane, and the DRB is used as a tunnel through which user data are transmitted on the user plane.

If an RRC connection is established between the RRC layer of the UE and the RRC layer of the E-UTRAN, the UE is in an RRC connected state. If not, the UE is in an RRC idle state.

Downlink transport channels through which data is transmitted from the network to the UE include a Broadcast Channel (BCH) through which system information is transmitted and a downlink Shared Channel (SCH) through which user traffic or control messages are transmitted. Traffic or control messages for a downlink multicast or broadcast service may be transmitted through the downlink SCH or may be transmitted through an additional downlink Multicast Channel (MCH). Meanwhile, an uplink transport channel through which data is transmitted from the UE to the network includes a Random Access Channel (RACH) through which an initial control message is transmitted and an uplink Shared Channel (SCH) through which user traffic or control messages are transmitted.

Logical channels placed above and mapped to transport channels include a Broadcast Control Channel (BCCH), a Paging Control Channel (PCCH), a Common Control Channel (CCCH), a Multicast Control Channel (MCCH), and a Multicast Traffic Channel (MTCH).

The physical channel includes a number of OFDM symbols in the time domain and a number of subcarriers in the frequency domain. One subframe includes a plurality of OFDM symbols in the time domain. The RB is a resource allocation unit and includes a plurality of OFDM symbols and a plurality of subcarriers. Further, each subframe may use a specific subcarrier for a specific OFDM symbol (e.g., a first OFDM symbol) of a corresponding subframe of a Physical Downlink Control Channel (PDCCH), i.e., L1/L2 control channel. A Transmission Time Interval (TTI) is a unit time for subframe transmission.

Fig. 4 shows a structure of an uplink subframe in 3GPP LTE.

The uplink subframe may be divided into a control region and a data region in a frequency domain. A Physical Uplink Control Channel (PUCCH) on which uplink control information is transmitted is allocated to the control region. A Physical Uplink Shared Channel (PUSCH) through which data is transmitted is allocated to the data region. The terminal may simultaneously transmit or not transmit PUCCH and PUSCH according to the configuration.

A PUCCH for one terminal is allocated as an RB pair in a subframe. RBs belonging to the RB pair occupy different subcarriers in the first slot and the second slot. The frequency occupied by the RB belonging to the RB pair allocated to the PUCCH varies based on the slot boundary. This is called that the RB pair allocated to the PUCCH has hopped in the slot boundary. The terminal can obtain a frequency diversity gain by transmitting uplink control information through different subcarriers as time passes.

The uplink control information transmitted on the PUCCH includes ACK/NACK, Channel State Information (CSI) indicating a downlink channel state, a Scheduling Request (SR), i.e., an uplink radio resource allocation request, and the like. The CSI includes a Precoding Matrix Index (PMI) indicating a precoding matrix, a Rank Indicator (RI) indicating a rank value preferred by the UE, a Channel Quality Indicator (CQI) indicating a channel state, and the like.

The PUSCH is mapped to an uplink shared channel (UL-SCH), i.e., a transport channel. The uplink data transmitted on the PUSCH can be a transport block, i.e., a data block for the UL-SCH transmitted during a TTI. The transport block can be user information. Alternatively, the uplink data can be multiplexed data. The multiplexed data can be obtained by multiplexing a transport block for UL-SCH and control information. For example, the control information multiplexed with the data can include CQI, PMI, ACK/NACK, RI, and the like. Alternatively, the uplink data may include only the control information.

Fig. 5 shows a structure of a downlink subframe in 3GPP LTE.

The downlink subframe includes two slots in the time domain, and each slot includes 7 OFDM symbols in the normal CP. The first 3 at most OFDM symbols in the first slot within the downlink subframe (i.e., the 4 at most OFDM symbols for 1.4MHz bandwidth) correspond to a control region allocated with a control channel, and the remaining OFDM symbols correspond to a data region allocated with a Physical Downlink Shared Channel (PDSCH). The PDSCH means a channel on which data is transmitted from a BS or a node to a UE.

The control channels transmitted in the control region include a Physical Control Format Indicator Channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), and a Physical Downlink Control Channel (PDCCH).

The PCFICH transmitted in the first OFDM symbol of the subframe carries a Control Format Indicator (CFI), i.e., information on the number of OFDM symbols used to transmit control channels within the subframe (i.e., the size of the control region). The terminal first receives the CFI on the PCFICH and then decodes the PDCCH. Unlike the PDCCH, the PCFICH does not use blind decoding, and is transmitted through a fixed PCFICH resource of a subframe.

The PHICH carries an Acknowledgement (ACK)/negative-acknowledgement (NACK) signal for uplink hybrid automatic repeat request (HARQ). An ACK/NACK signal for uplink data transmitted by the UE is transmitted through a PHICH. The PHICH will be described in detail later.

The PDCCH is a control channel on which Downlink Control Information (DCI) is transmitted. The DCI can include an allocation of PDSCH resources (also referred to as a downlink grant (DL grant)), an allocation of Physical Uplink Shared Channel (PUSCH) resources (also referred to as an uplink grant (UL grant)), a set of transmit power control commands for individual UEs within a particular terminal group, and/or activation of voice over internet protocol (VoIP).

Fig. 6 shows an example of a method of performing uplink HARQ in 3GPP LTE.

The terminal receives allocation of initial uplink resources from the BS on the PDCCH 310 in the nth subframe.

The terminal transmits uplink data, more specifically, an uplink transport block, on the PUSCH320 in the (n +4) th subframe using the allocation of the initial uplink resource.

The BS transmits an ACK/NACK signal for an uplink transport block on PHICH 331 in the (n +8) th subframe. The ACK/NACK signal indicates acknowledgement of reception of the uplink transport block, the ACK signal indicates successful reception, and the NACK signal indicates unsuccessful reception.

The terminal having received the NACK signal transmits a retransmission block on the PUSCH 340 in the (n +12) th subframe.

The BS transmits an ACK/NACK signal for an uplink transport block on the PHICH 351 in the (n +16) th subframe.

After the initial transmission in the (n +4) th subframe, retransmission is performed in the (n +12) th subframe. Therefore, HARQ is performed using 8 subframes as HARQ periods.

In 3GPP LTE, 8 HARQ processes can be performed. HARQ processes are assigned indices from 0 to 7. The foregoing example shows HARQ in HARQ process index 4.

In the following, a new radio access technology (new RAT, NR) will be described.

As more and more communication devices require more communication capacity, there is a need for improving mobile broadband communications over existing radio access technologies. In addition, large-scale Machine Type Communication (MTC) that provides various services by connecting many devices and objects is one of major issues to be considered in next-generation communication. In addition, communication system design is being discussed that considers reliability/delay sensitive services/UEs. The introduction of next generation radio access technologies considering enhanced mobile broadband communication (eMBB), large-scale mtc (mtc), ultra-reliable and low-latency communication (URLLC) is discussed. For convenience, this new technology may be referred to as a new radio access technology (new RAT or NR) in the present invention.

Fig. 7 illustrates a system structure of a next generation radio access network (NG-RAN) to which NR is applied.

Referring to fig. 7, the NG-RAN may include a gNB and/or an eNB that provides user plane and control plane protocol termination to the terminal. Fig. 7 illustrates a case where only the gNB is included. The gNB and the eNB are connected via an Xn interface. The gNB and the eNB are connected to a 5G core network (5GC) via an NG interface. More specifically, the gNB and the eNB are connected to an Access and mobility management function (AMF) via a NG-C interface and to a User Plane Function (UPF) via a NG-U interface.

Fig. 8 illustrates a functional division between the NG-RAN and the 5 GC.

The gNB may provide functions such as inter-cell radio resource management (inter-cell RRM), radio bearer management (RB control), connection mobility control, radio admission control, measurement configuration and provisioning, dynamic resource allocation, and so forth. The AMF may provide functions such as NAS security, idle state mobility handling, etc. The UPF may provide functions such as mobility anchoring, PDU processing, and the like. SMF may provide functions such as UE IP address assignment, PDU session control, etc.

Fig. 9 illustrates an example of a frame structure for a new radio access technology.

In NR, a structure in which a control channel and a data channel are time-division multiplexed within one TTI as shown in fig. 9 can be regarded as a frame structure to minimize delay.

In fig. 9, a shaded area represents a downlink control area, and a black area represents an uplink control area. The remaining region may be used for Downlink (DL) data transmission or Uplink (UL) data transmission. This structure is characterized in that DL transmission and UL transmission are sequentially performed within one subframe, and thus DL data can be transmitted and UL ACK/NACK can be received within the subframe. Accordingly, the time required from the occurrence of a data transmission error to the retransmission of data is reduced, thereby minimizing the delay in the final data transmission.

In this data and control TDMed subframe structure, a time gap may be required for the base station and the terminal to switch from a transmission mode to a reception mode or from a reception mode to a transmission mode. For this, some OFDM symbols at the time of DL switching to UL may be set as a Guard Period (GP) in the self-contained subframe structure.

Meanwhile, the following technique may be applied in association with the uplink of NR.

< PUCCH Format in NR >

In NR, the PUCCH format may have the following characteristics.

The PUCCH may deliver Uplink Control Information (UCI). In addition, PUCCH formats may be distinguished from each other according to duration/payload size. For example, PUCCH formats may be classified into a "short-duration uplink control channel (SHD _ PUCCH)" and a "long-duration uplink control channel (LGD _ PUCCH)". For simplicity, SHD _ PUCCH may be referred to as short PUCCH, and herein, format 0(≦ 2 bits) and format 2(>2 bits) may correspond to the short PUCCH. For simplicity, LGD _ PUCCH may be referred to as long PUCCH, and herein, format 1(≦ 2 bits), format 3(>2, [ > N ] bits), and format 4(>2, [ ≦ N ] bits) may correspond to the long PUCCH.

Meanwhile, the transmission diversity method for the PUCCH may not be supported in release 15. Additionally, synchronized Physical Uplink Shared Channel (PUSCH) and PUCCH transmissions may not be supported in release 15.

Meanwhile, the PUCCH format in NR may be defined as shown in the following table 1.

[ Table 1]

< Uplink (UL) Signal/channel multiplexing >

In NR, Uplink (UL) signal/channel multiplexing may have the following characteristics.

For multiplexing of PUCCH and PUSCH, the following techniques may be supported. For example, a Time Division Multiplexing (TDM) technique (or scheme) may be supported between a short PUCCH (e.g., format 0/2) and a PUSCH. In addition, for example, a Frequency Division Multiplexing (FDM) technique (or scheme) may be supported between a short PUCCH (e.g., format 0/2) and a PUSCH corresponding to a slot with a short uplink portion (UL portion) of a UE (other than release 15).

For multiplexing of PUCCH and PUSCH, the following techniques may be supported. For example, a TDM/FDM technique (or scheme) may be supported between a short PUCCH (e.g., format 0/2) and a long PUCCH (e.g., format 1/3/4). In addition, for example, TDM techniques (or schemes) may be supported between short PUCCHs (e.g., format 0/2) within the same slot of a single UE. Also, for example, TDM techniques (or schemes) may be supported between a short PUCCH (e.g., format 0/2) and a long PUCCH (e.g., format 1/3/4) within the same slot of a single UE.

As described above, fig. 10 shows an example of a multiplexing scheme within a single slot in NR.

Referring to fig. 10, fig. 10 shows an example in which a long PUCCH is positioned in different bands from symbol #3 to symbol #7 and from symbol #8 to symbol #11 in an Uplink (UL) region within a single slot. Also, fig. 10 also shows an example in which each short PUCCH is positioned in symbol #12 and symbol #13, respectively. More specifically, fig. 10 shows an example in which TDM is performed between short PUCCHs, and in which TDM/FDM is performed between a short PUCCH and a long PUCCH.

< control information Modulation and Coding Scheme (MCS) offset >

In NR, both semi-persistent and dynamic indications may be supported for β offset. In addition, for dynamic β -offset indication, multiple β -offset value sets may be configured through RRC signaling, and UL grant may dynamically indicate an index of the set. Here, each set may include a plurality of entries, and each entry may correspond to each UCI type (including a case where two-part CSI can be applied).

< UCI mapping >

For slot-based scheduling, the PUSCH may be processed by rate matching for HARQ-ACKs exceeding 2 bits, and may be processed by puncturing (puncturing) for HARQ-ACKs less than or equal to 2 bits.

In NR, the case where Downlink (DL) assignments mapped to the same time instance for HARQ-ACK transmission within PUSCH are later than UL grant may not be supported.

In addition, UCI (e.g., HARQ-ACK or CSI) piggybacked within PUSCH may be mapped to REs dispersed and distributed in RBs assigned to PUSCH.

The same RE mapping rules may be applied for HARQ-ACK piggybacking within PUSCH regardless of HARQ-ACK puncturing or PUSCH rate matching. For example, localized mapping or distributed mapping may be performed adjacent to the DM-RS in the time domain.

< scheduling/HARQ timing >

In NR, scheduling/HARQ timing may have the following features.

For dynamic indication of scheduling/HARQ timing, the slot timing between a and B may be indicated by a field within the DCI from a set of values, and the set of values may be configured by UE-specific RRC signaling. Here, all release 15 UEs may support a minimum value of K0, such as 0.

Meanwhile, K0 to K2 of a and B may be defined as shown in table 2 below.

[ Table 2]

	A	B
			K0	Downlink scheduling DCI	Corresponding downlink data transmission
K1	Downlink data reception	Corresponding HARQ-ACK
			K2	Uplink scheduling DCI	Corresponding uplink data transmission

The UE processing time capability may be indicated by symbols (N1, N2). Here, N1 may indicate the number of OFDM symbols required for the UE's processing from the end of NR-PDSCH reception to the earliest possible start of its corresponding ACK/NACK transmission from the UE's perspective. And N2 may indicate the number of multiple OFDM symbols required for processing by the UE from the end of the NR-PDCCH including the UL grant receptions to the earliest possible start of its corresponding NR-PUSCH transmission from the UE's perspective.

The minimum value of (K1, K2) for a UE may be determined based on (N1, N2), Timing Advance (TA) value, UE DL/UL handover, etc.

Meanwhile, in NR, two types of UE processing time capability may be defined for slot-based scheduling corresponding to the case of using a single parameter set for at least PDCCH, PDSCH and PUSCH.

For example, for a given setting and parameter set, the UE may indicate only one capability for N1 (or N2) based on entries of respective N1 (or N2) from the following two tables (table 3, table 4).

Capacity #1 (table 3): UE processing time capability

[ Table 3]

Capacity #2 (table 4): active UE processing time capability

[ Table 4]

For a hybrid parameter set and scheduling/HARQ timing, when the parameter sets between PDCCH and transmission scheduled by PDCCH are different from each other, for K0 or K2, the time granularity indicated by DCI may be based on the scheduled transmission.

HARQ-ACK transmissions associated with multiple DL element carriers operating based on the same or different sets of parameters may be supported. The time granularity indicated by the DCI scheduling the PDSCH may be based on a set of parameters for the PUCCH transmission.

< Code Block Group (CBG) -based (re) Transmission >

And (3) synchronization: partial Transport Block (TB) retransmissions may lead to an efficient use of resources. The retransmission unit may correspond to a Code Block Group (CBG). However, when this method is used, HARQ-ACK feedback bits and DCI overhead may be increased.

Code Block Group (CBG) configuration: the UE may be semi-persistent configured such that CBG-based retransmissions can be performed via RRC signaling. The maximum value N of CBG per TB may be set through RRC signaling. In case of a single Codeword (CW), the maximum value of CBG per TB that can be set may be equal to 8. In the case of multiple CWs, the maximum value of CBGs per TB that can be set may be equal to 4, and the set maximum value of CBGs per TB may be the same in each TB.

At least in the case of a single CW, the number of CBGs in the TB may be equal to min (C, N), and here, C may indicate the number of CBs within the TB. Of the total M CBGs, the first Mod (C, M) CBG may include ceil (C/M) CBs per CBG. The remaining M-Mod (C, M) CBGs may include floor (C/M) CBs per CBG.

As for DCI, CBG transmission information (CBGTI) and CBG removal information (CBGFI) may be employed. CBGTI: the CBG may be (re-) transmitted and this may correspond to N bits of the CBGTI configured by RRC. CBGFI: CBG may be handled differently for soft buffering/HARQ combining, and this may correspond to another 1 bit of CBGFI (in case of at least a single CW).

For downlink data, CBGTI and CBGFI may be included in the same DCI. In mode 1, the DCI may include CBGTI. In mode 2, the DCI may include both CBGTI and CBGFI.

For uplink data, the CBGTI may be configured to be included in the DCI. In mode 1, the DCI may include CBGTI.

In HARQ-ACK feedback, there may be the same set of CBs in each CBG of a TB for initial transmission and retransmission. When CBG-based retransmission is configured, the UE may use TB-level HARQ-ACK feedback for the PDSCH scheduled by the PDCCH using fallback DCI, at least without performing HARQ-ACK multiplexing. This may indicate that the fallback DCI does not support CBG level HARQ-ACK feedback.

For a semi-persistent HARQ-ACK codebook, the HARQ-ACK codebook may include HARQ-ACKs corresponding to all configured CBGs, including non-scheduled CBGs. If the same CBG is successfully decoded, an ACK may be reported for the corresponding CBG. If the TB CRC is not passed when the CB CRC check is passed for all CBs, a NACK may be reported for all CBGs. NACK may be mapped to a blank CBG index if the number of CBs of the TB is less than a predetermined maximum CBG number.

Hereinafter, the present invention will be described in detail.

As described above, in NR, discussion is being made based on a communication system design considering a service/terminal (or UE) sensitive to reliability and latency. In addition, introduction of a next generation radio access technology considering ultra-reliable and low-delay communication (URLLC) and the like is also under discussion.

Meanwhile, data retransmission through a hybrid automatic repeat request (HARQ) process may also be performed in the NR. However, in NR, by defining a channel extended in a unit of system bandwidth, a more efficient use method using consumed symbols is being discussed. And, therefore, discussion is also being made regarding a method of performing a HARQ process without employing a Physical HARQ Indicator Channel (PHICH) in the related art LTE.

Accordingly, the present invention uses Downlink Control Information (DCI) as a retransmission indicator, so that a method of performing retransmission (or retransmission) of data by a terminal (or User Equipment (UE)) is provided.

For example, the methods proposed below respectively propose methods for efficiently triggering retransmission of multiple (uplink (UL)/Downlink (DL)) data (synchronization). Here, the first and second liquid crystal display panels are, for example, more specifically, it may be understood that instead of (additionally) transmitting a retransmission-related scheduling grant, scheduling information related to initial transmission is also (fully or partially) used for retransmission (and/or "adaptive retransmission (a-RETX)" (e.g., may be performed based on a retransmission-related scheduling grant (and/or a HARQ feedback channel related to whether data reception was successful or not)). Here, for example, the term "non-adaptive retransmission (NA-RETX)" used in the present invention may be understood (or interpreted) as (expansively or interchangeably) the term "adaptive retransmission (a-RETX)". In addition, the term "retransmission indication" used in the present invention may be expansively understood (or interpreted) as "new Transport Block (TB) indication".

Fig. 11 is a flowchart illustrating a method for retransmitting data of a UE according to an exemplary embodiment of the present invention.

According to fig. 11, a User Equipment (UE) receives Downlink Control Information (DCI) from a network (S1110). At this time, the DCI includes an acknowledgement/negative acknowledgement (ACK/NACK) field or a retransmission indication field.

Thereafter, the UE retransmits the data based on the DCI (S1120). Here, for example, the retransmission may correspond to a non-adaptive retransmission. In addition, for example, the DCI may indicate retransmission per HARQ process ID. In addition, for example, the DCI may indicate a retransmission per subframe within a subframe window. In addition, for example, in case of defining a counter field indicating a scheduling index within an Uplink (UL) grant, the DCI may signal a last counter value. In addition, for example, in the case where a polling on/off field is defined within the UL grant, and when a polling on UL grant is received in the nth subframe, the UL grant, which is an indication target of DCI received after the time point of the nth subframe, may correspond to an uplink grant received during the duration from the reception point of the most recent polling on uplink grant before the nth subframe to the (N-1) th subframe. In addition, for example, the DCI may correspond to UE-specific DCI or UE-common DCI. In addition, for example, the DCI may include at least any one of a non-adaptive retransmission on/off field, a non-adaptive retransmission timing field, a Redundancy Version (RV) field, and an aperiodic Channel State Information (CSI) transmission request field. In addition, for example, a Radio Network Temporary Identifier (RNTI) value related to the detection of DCI may be independently signaled. In addition, for example, transmission-related parameters within the search space for DCI may be predetermined. In addition, for example, in the case where the UE receives DCI and an uplink grant for the same HARQ process ID, retransmission may be performed according to the uplink grant. In addition, for example, a HARQ ACK transmission timing field may be configured per HARQ process ID within DCI. Also, for example, an acknowledgement/negative Acknowledgement Resource Indicator (ARI) field may be configured per HARQ process ID within DCI.

Hereinafter, a detailed example of a method for retransmitting data of a User Equipment (UE) according to fig. 11 will be described in detail.

As described above, the UE receives Downlink Control Information (DCI) from the network and retransmits data based on the DCI. Here, the DCI may include an acknowledgement/negative acknowledgement (ACK/NACK) field. In other words, in the related art 3GPP LTE, although the UE has received ACK/NACK on the PHICH, instead of doing so, in the present invention, the UE receives DCI including an ACK/NACK field and then performs a HARQ process on data based on the received DCI. Additionally, the retransmission may correspond to a non-adaptive retransmission. Hereinafter, a detailed example of this process will be described below.

[ proposed method #1] for example, when NA-RETX of multiple (uplink) data is triggered by a single (predefined) indicator (e.g., "DCI") (NA-RETXINDI) (synchronization), the following (partial) rule may be applied.

As described above, the DCI may indicate retransmission of each hybrid automatic repeat request process identifier (HARQ process ID). Hereinafter, a detailed example of this process will be described below.

(example #1-1-1) for example, NA-RETX may be indicated according to HARQ process (group) ID.

Here, for example, a field (or fields) of the NA-RETX indication per HARQ process (group) ID within the NA-RETX ndi may be defined, with the corresponding rule applied.

Here, for example, the inter-working HARQ process (group) ID of each field (index) may be configured according to a predefined rule (e.g., a structure that (implicitly) maps a relatively low (or high) HARQ process ID to a relatively low field index) and/or may be signaled (e.g., RRC signaling) (from the base station).

As described above, the DCI may indicate a retransmission per subframe within a subframe window. In addition, in case of defining a counter field indicating a scheduling index within an Uplink (UL) grant, DCI may signal a last counter value. In other words, for example, when the counter value of the UL grant is equal to 5, the number of UL grants corresponding to the counter value may be a target of retransmission trigger. Here, it is not considered whether retransmission of uplink data is actually required in the network.

In addition, when DCI is received, a counter value may be initialized. In other words, in the case of transmission based on the above-described counter value, retransmission may be excessively required for data actually received by the network. Here, excessive retransmission as shown in the above example can be prevented by using DCI that initializes a counter value.

In addition, in case that a polling on/off field is defined within the UL grant, and when a polling on UL grant is received in the nth subframe, the UL grant, which is an indication target of DCI received after a time point of the nth subframe, may correspond to an uplink grant received within a duration from a reception point of a most recent polling on uplink grant before the nth subframe to the (N-1) th subframe. In other words, by adjusting the interval between two polling UL grants received by the UE, the data retransmission duration can be adjusted. Hereinafter, a detailed example of this process will be described below.

(examples #1-1-2) for example, NA-RETX may be indicated per subframe (group) within a subframe window (RETX _ SFWIN).

Here, for example, a field (or fields) of the NA-RETX indication of the per-subframe (group) index (within RETX _ SFWIN) within the NA-RETX index may be defined, with the corresponding rule applied.

Here, for example, if a subframe is included in RETX _ SFWIN, the "subframe (group) index" expression may also be interpreted (in the present invention) as an index finally derived after performing re-indexing.

Here, for example, the interlink subframe (group) index of each field (index) may be configured according to a predefined rule (e.g., a structure that (implicitly) maps a relatively low (or high) subframe (group) index to a relatively low field index), and/or may be signaled (e.g., RRC signaling) from the (base station).

Here, for example, NA-RETX indicates a target subframe window size (RETX _ SFWINSIZE) may be signaled (e.g., RRC signaling) from a (base station) and/or may be signaled via NA-RETX ndi (a field defined therein for a corresponding purpose) (or a newly defined indicator).

As another example, in case a counter (SCH _ CNT) field is defined that indicates the scheduling index within the UL grant (e.g. a function similar to the (legacy) "Downlink Assignment Index (DAI)" field), the LAST counter value (LAST _ CVAL) (related to retransmission trigger) may be signaled within NA-RETXINDI (through a predefined field) (e.g.,' 0- (LAST _ CVAL-1) "counter value of the UL grant becomes NA-RETX (synchronization) trigger target (in this case)).

Here, for example, the SCH _ CNT value may be configured to be initialized after NA-RETXINDI transmission/reception.

Here, for example, by doing so, it is possible to perform (a) a dynamic shift (/ indication) of RETX _ SFWIN (and/or RETX _ SFWINSIZE) and/or (B) signaling of information on the number of (total) HARQ processes (groups) ID (or subframes (groups)), wherein the presence or absence of NA-RETX is to be indicated via (respective) NA-RETXINDI.

As another example, in the case of defining a "polling on/off" field (e.g., "1-on", "0-off") within a UL grant, if "UL grant W/polling on/off" is received at an SF # N time point, then (a) will indicate that the NA-RETX (presence or absence), which is NA-RETX ndi received (earliest) after a time point including a time point of SF # N (or SF # (N +1)), is a target UL grant definition (/ hypothesis) that a duration (or duration) from a "UL grant W/polling on/off 1" reception point (K) positioned at a latest point before the SF # N time point to an SF # (N-1) time point (or a duration from the SF # (K +1) time point to the SF # N time point) is received for all UL grants, and/or (B) rettx _ SFWIN of NA-RETXINDI received (earliest) after a time point including an SF # N (or SF # (N +1)) time point becomes a duration from an SF # K time point to an SF # (N-1) time point (or a duration from an SF # (K +1) time point to an SF # N time point).

Fig. 12 illustrates an overall view of a data retransmission method according to an exemplary embodiment of the present invention.

According to fig. 12, for example, there may be 6 HARQ process IDs, such as HARQ process IDs #0, #1, #2, #3, #4, and # 5. Here, the UE may receive DCI in subframe N. Here, for example, data retransmission of subframes K, K +1, K +2, K +3, K +4, and K +5 via DCI may be considered. Here, HARQ process IDs #0 to #5 may be serially configured to correspond to subframes K to K + 5. Here, for example, when the UE receives the bit sequence 001010 through the received DCI, the UE may perform retransmission for HARQ process IDs #2 and # 4.

Also, here, for example, a duration starting from subframe K to K +5 may be configured into a subframe window via the received DCI, and retransmission of each subframe within the window may be indicated via the received DCI.

Fig. 13 illustrates an overall view of a data retransmission method according to an exemplary embodiment of the present invention.

Referring to fig. 13, the UE may receive DCI in an nth subframe. Here, for example, scheduling may be performed through an Uplink (UL) grant for the K subframe to the (K +4) subframe. Here, in case of defining a counter field indicating a scheduling index within an Uplink (UL) grant, counter values of 0, 1,. 5 may be assigned to subframes K to K +4, respectively. Here, by signaling the last counter value from the received DCI, retransmission can be performed on all data transmitted from the K-th subframe to the (K +4) -th subframe.

Here, whether the network actually receives the retransmitted data is not a subject to be considered. Here, for example, the counter value is initialized after DCI reception, and by adjusting the transmission time point of DCI, excessive data retransmission can be prevented.

Fig. 14 illustrates an overall view of a data retransmission method according to an exemplary embodiment of the present invention.

According to fig. 14, the UE receives a poll on UL grant from the nth subframe. Here, a subframe in which the last polling on uplink grant is received before the nth subframe may correspond to a kth subframe (where K < N). In addition, here, a subframe in which the latest DCI is received after the nth subframe may correspond to the pth subframe (where P > N). Here, the UL grant corresponding to the retransmission target indicated by the DCI received through the pth subframe may correspond to a UL grant received during a duration from a time point of the kth subframe to a time point of the (N-1) th subframe (where N-1> K).

As described above, the DCI may correspond to a UE-specific DCI or a DCI common to UEs. Hereinafter, a detailed example of this process will be described below.

(examples #1-2) NA-RETXINDI may be configured (/ defined), for example, to have a "UE-specific DCI" structure.

Here, for example, the payload size of the corresponding NA-RETXINDI may be configured (/ defined) to be the same as (generic) UL grant (e.g., DCI format 0(/4)) (e.g., (in this case) whether the configuration corresponds to (generic) UL grant or NA-RETXINDI is determined based on a "FLAG field," which is predefined (within the NA-RETXINDI) and/or the payload size may be independently configured (/ defined).

For example, NA-RETXINDI may be configured (/ defined) to have a "UE (group) -common DCI" structure. Here, for example, NA-RETXINDI similar to the (legacy) "DCI format 3/3 a" may trigger NA-RETX independently for each UE in a state where different MULTI-BITs are assigned to multiple UEs within a single DCI, applying the corresponding rule.

As described above, the DCI may include at least any one of a non-adaptive retransmission on/off field, a non-adaptive retransmission timing field, a Redundancy Version (RV) field, and an aperiodic Channel State Information (CSI) transmission request field. Hereinafter, a detailed example of this process will be described below.

(examples #1-3) for example, the following fields may be defined (in part) within NA-RETXINDI (per UE).

Here, for example, depending on the number of data transmissions (of different HARQ process (group) IDs) actually performed in RETX _ SFWIN, the (total) number of specific fields to be defined in NA-RETX ndi may vary. (e.g., in case "N" actual data transmissions (of different HARQ process (group) IDs) are performed within RETX SFWIN, (total) "N-RETX ON/OFF" fields may be defined (/ configured) in NA-RETX ndi.

- "NA-RETX ON/OFF (e.g., operationally equivalent to PHICH A/N (acknowledgement/negative acknowledgement))" field

Here, for example, "1-BIT" may be assigned by HARQ process (group) ID (or subframe (group)).

- "NA-RETX TIMING" field

Here, for example, (a) (individual) "NA-RETX TIMING" field may be configured (/ defined) by HARQ process (group) ID (or subframe (group)) and/or (B) only one (primary) "NA-RETX TIMING" field may be configured (/ defined), and NR-RETX may be continuously performed in an increasing (or decreasing) format (in the time domain) of HARQ process (group) ID (or subframe (group) index) based on the indicated (NA-RETX) TIMING.

As another example, pre-configured (/ signaled (e.g., via RRC signaling)) fixed (NA-RETX) TIMING may be applied without any separate "NA-RETX TIMING" field configuration (/ definition) within the NA-RETX ndi.

Here, for example, the corresponding (NA-RETX) timing may be differently (or identically) specified for each HARQ process (group) ID (or subframe (group) index).

- "Redundancy Version (RV)" field

Here, for example, (a) (individual) "RV" field may be configured (/ defined) by HARQ process (group) ID (or subframe (group)) and/or (B) only one (primary) "RV" field may be configured (/ defined), and the indicated RV value may be commonly applied to all HARQ process (group) ID (or subframe) related NA-RETX.

As another example, a pre-configured (/ signaled (e.g., via RRC signaling)) fixed RV value (semi-persistent) may be applied without any separate "RV" field configuration (/ definition) within NA-RETXINDI.

Here, for example, the corresponding RV value may be differently (or identically) designated for each HARQ process (group) ID (or subframe (group) index).

- "aperiodic CSI (/ SRS) Transmission request" field

Here, for example, in case an aperiodic CSI (/ SRS) transmission is requested, (a) (which is (synchronously) triggered to the respective NA-RETXINDI) all NA-RETX(s) may be configured to apply the aperiodic CSI (/ SRS) transmission, and/or (B) a specific (or part of) NA-RETX information to which the aperiodic CSI (/ SRS) transmission is to be applied may be configured to be signaled by the NA-RETXINDI (a field defined therein for a corresponding purpose) (or a newly defined indicator), and/or (C) the aperiodic CSI (/ SRS) transmission may be applied only to a (single) specific NA-RETX (e.g., the first (or last) NA-RETX) that is pre-configured (/ signaled (e.g., via RRC signaling)).

- "(NA-RETX correlation) HARQ process (group) ID (or subframe (group) index)" field

- "(within NA-RETXINDI) number of total HARQ process (group) IDs (or sub-frame (group)) expected to indicate (execution or non-execution) of NA-RETX" field

- "(NA-RETX related) DM-RS Cyclic Shift (CS) index" field (and/or "(NA-RETX related) transmission power command" field and/or "(NA-RETX related) (analog)) beam related information" field and/or "(NA-RETX related) carrier (or (sub) band) (index) indicator" "field (and/or (retransmission related) MCS" field and/or "(retransmission) related (frequency) resource allocation" field))

As described above, a Radio Network Temporary Identifier (RNTI) value related to the detection of DCI may be independently signaled. In addition, the transmission-related parameters within the search space for DCI may be predetermined in advance. Hereinafter, a detailed example of this process will be described below.

(examples #1-4) for example, the NA-RETXINDI (blind) detection related RNTI value may be signaled independently or (differently) from the (C-) RNTI value (for legacy DCI (with the same payload size) (e.g., DCI format 0(/ 4))). for example, the NA-RETXINDI transmission (/ detection) related parameters (e.g., (E) PDCCH candidate locations, (lowest) Aggregation Level (AL), number of blind decodes per AL, etc.) within the Search Space (SS) (common to UE-specific or (UE group)) may be pre-configured (/ signaled (e.g., via RRC signaling)).

In addition, in case that the UE receives DCI and an uplink grant for the same HARQ process ID, retransmission may be performed according to the uplink grant. Hereinafter, a detailed example of this process will be described below.

(examples #1-5) for example, in case the UE receives all (above) NA-RETXIND (indicating retransmission) and (generic) (a-RETX) UL GRANTs (e.g. DCI format 0(/4)), for the same HARQ process (group) ID (or subframe (group) index), the UE may be configured to perform retransmission according to (a-RETX) GRANT (or NA-RETXINDI).

Here, for example, the (a-RETX) UL grant may be interpreted as having a relatively higher (or lower) priority (in terms of retransmission indication) than NA-RETX ndi, with the corresponding rule applied.

As described above, a HARQ Acknowledgement (ACK) transmission timing field may be configured per HARQ process ID within DCI. Hereinafter, a detailed example of this process will be described below.

[ proposed method #2] for example, in the case where the above-mentioned proposed method (part) is applied to NA-RETX (and/or a-RETX) for a plurality of downlink data, the following rule (part of) may be (additionally) applied.

(example #2-1) the retransmission-related HARQ-ACK transmission TIMING (HQTX _ TIMING) may be determined according to (part of) the following rule, for example.

(rule #2-1-1) for example, within the NA-RETXINDI, (a) may configure (/ define) (individual) "hqttx _ TIMING" fields for each HARQ process (group) ID (or subframe (group)), and/or (B) may configure (/ define) only one (master) "hqttx _ TIMING" field, and based on the indicated HARQ-ACK transmission TIMING, HARQ-ACK transmission may be performed serially (in the time domain) in an increasing (or decreasing) format of the HARQ process (group) ID (or subframe (group) index), and/or (c) may configure (/ define) only one (master) "HQTX _ TIMING" field, HARQ-performance of "aggregation" for HARQ-retransmissions (synchronous (ACKs) (triggered to the corresponding NA-RETXINDI) corresponding to all HARQ process (group) IDs (or subframe (group) indices) at the indicated HARQ-ACK transmission TIMING), and, then, the aggregation result may be transmitted.

As another example, a pre-configured (/ signaled (e.g., via RRC signaling)) fixed HARQ-ACK transmission TIMING (semi-persistent) may be applied without any separate "HQTX _ TIMING" field configuration (/ definition) within the NA-RETXINDI. Here, for example, the corresponding HARQ-ACK transmission timing may be differently (or identically) specified for each HARQ process (group) ID (or subframe (group) index).

As described above, an acknowledgement/negative acknowledgement (a/N) resource indicator (ARI) field may be configured per HARQ process ID within DCI, and a Physical Uplink Control Channel (PUCCH) resource may be assigned based on the ARI. Hereinafter, a detailed example of this process will be described below.

(example #2-2) "a" PUCCH resource (PUCCH _ RSC) "related to retransmission may be determined according to (part of) the following rule, for example.

(rule #2-2-1) for example, within NA-RETXINDI, (a) each HARQ process (group) ID (or subframe (group)) may configure (/ define) (individual) "a/N resource indicator (ARI)" fields, and/or (B) may configure (/ define) only one (primary) "ARI" field, and PUCCH _ RSC corresponding to the indicated ARI may be commonly assigned to all HARQ process (group) IDs (or subframe (group) indices) (synchronous (retransmission) triggered to the corresponding NA-RETXINDI).

As another example, a pre-configured (/ signaled (e.g., via RRC signaling)) fixed PUCCH _ RSC may be assigned without any separate "ARI" field configuration (/ definition) within NA-RETXINDI.

Here, for example, the corresponding PUCCH _ RSC may be differently (or identically) designated for each HARQ process (group) ID (or subframe (group) index).

Fig. 15 shows a detailed example of applying the method of fig. 11.

According to fig. 15, a User Equipment (UE) transmits uplink data to a base station (S1510).

Thereafter, the base station measures whether to receive uplink data (S1520).

Subsequently, the base station transmits DCI including an Acknowledgement (ACK) field based on the measurement result to the UE (S1530).

Thereafter, the UE retransmits the data based on the DCI (S1540). Here, for example, the retransmission may correspond to a non-adaptive retransmission. In addition, for example, the DCI may indicate retransmission per HARQ process ID. In addition, for example, the DCI may indicate a retransmission per subframe within a subframe window. In addition, for example, in case of defining a counter field indicating a scheduling index within an Uplink (UL) grant, DCI may signal a last counter value. In addition, for example, in the case where a polling on/off field is defined within the UL grant, and when a polling on UL grant is received in the nth subframe, the UL grant, which is an indication target of DCI received after the time point of the nth subframe, may correspond to an uplink grant received during the duration from the reception point of the most recent polling on uplink grant before the nth subframe to the (N-1) th subframe. In addition, for example, the DCI may correspond to a UE-specific DCI or a DCI common to UEs. In addition, for example, the DCI may include at least any one of a non-adaptive retransmission on/off field, a non-adaptive retransmission timing field, a Redundancy Version (RV) field, and an aperiodic Channel State Information (CSI) transmission request field. In addition, for example, a Radio Network Temporary Identifier (RNTI) value related to the detection of DCI may be independently signaled. In addition, for example, the transmission-related parameters within the search space for DCI may be predetermined in advance. In addition, for example, in a case where the UE receives both DCI and an uplink grant for the same HARQ process ID, retransmission may be performed according to the uplink grant. In addition, for example, a HARQ ACK transmission timing field may be configured per HARQ process ID within DCI. Also, for example, an acknowledgement/negative Acknowledgement Resource Indicator (ARI) field may be configured per HARQ process ID within DCI.

Here, since a detailed example of UE retransmission data is the same as the description given above, a detailed description thereof will be omitted for simplicity.

Fig. 16 is a block diagram illustrating a communication device in which an embodiment of the invention is implemented.

Referring to fig. 16, the BS 100 includes a processor 110, a memory 120, and a Radio Frequency (RF) unit 130. The processor 110 implements the proposed functions, procedures and/or methods. The memory 120 is connected to the processor 110, and the memory stores various types of information for driving the processor 110. The RF unit 130 is connected to the processor 110, and transmits and/or receives a radio signal.

The User Equipment (UE)200 may include a processor 210, a memory 220, and an RF unit 230. The processor 210 implements the proposed functions, procedures and/or methods. For example, the processor 210 may receive uplink communication-related parameters set independently for each analog beam and apply the parameters to perform uplink communication. Here, when uplink communication is performed using a specific analog beam, the uplink communication-related parameters set in the specific analog beam may be applied to the uplink communication. The memory 220 is connected to the processor 210, and stores various types of information for driving the processor 210. The RF unit 230 is connected to the processor 210, and transmits and/or receives a radio signal.

The processors 110, 210 may include Application Specific Integrated Circuits (ASICs), other chipsets, logic circuits, data processors, and/or converters for converting baseband signals and radio signals. The memory 120, 220 may include Read Only Memory (ROM), Random Access Memory (RAM), flash memory, memory cards, storage media, and/or other storage devices. The RF unit 130, 230 may include one or more antennas for transmitting and/or receiving radio signals. When the embodiments are implemented in software, the above-described schemes may be implemented as modules (procedures, functions, and so on) for performing the above-described functions. The modules may be stored in the memory 120, 220 and executed by the processor 110, 210. The memory 120, 220 may be placed inside or outside the processor 110, 210 and connected to the processor 110, 210 using various known means.

Since an example of the proposed method above can be included as one of the implementation methods of the present invention, it is obvious that a corresponding example can be regarded (and understood) as one of the proposed methods. In addition, although the proposed methods described above can be implemented independently, the present invention can also be implemented as a combined (or integrated) structure of parts of the proposed methods. For example, the scope of a system adopting the proposed method of the present invention can be extended to systems other than the 3GPP LTE system.

The above-described exemplary embodiments include various examples. It will be obvious to those skilled in the art that combinations of all possible examples of the invention cannot be fully described, and that other combinations can be derived from the detailed description of the specification set forth herein, as will be apparent to those skilled in the art. Therefore, the scope of the present invention should be understood and determined by combining various examples presented in the detailed description of the present invention without departing from the scope and spirit of the present invention.

Claims (16)

1. A method of receiving acknowledgement/negative acknowledgement (ACK/NACK) information in a wireless communication system, the method performed by a User Equipment (UE) comprising:

receiving first Downlink Control Information (DCI) including an Uplink (UL) grant from a network;

transmitting uplink data to the network; and

receiving second DCI for feedback on the uplink data from the network; and

wherein the second DCI includes a Transmit Power Control (TPC) command for retransmission and ACK/NACK information scheduled by the second DCI,

wherein the ACK/NACK information relates to a plurality of hybrid automatic repeat request (HARQ) process Identifiers (IDs),

wherein the ACK/NACK information comprises a plurality of bits,

wherein each of the plurality of HARQ process IDs is related to a corresponding one of the plurality of bits in ascending order,

wherein a payload size of the second DCI is the same size as a payload size of the first DCI, and

wherein the second DCI is identified based on a flag in the second DCI.

2. The method of claim 1, further comprising:

retransmitting the uplink data based on the second DCI, wherein the retransmission is a non-adaptive retransmission.

3. The method of claim 1, wherein the second DCI notifies retransmissions per subframe within a subframe window.

4. The method of claim 1, wherein the second DCI signals a last counter value in case of a counter field defining a notification scheduling index within the UL grant.

5. The method of claim 4, wherein the counter value is initialized when the second DCI is received.

6. The method of claim 1, wherein, in case a polling on/off field is defined within the UL grant, and when a polling on UL grant is received in an nth subframe, the UL grant targeted for the DCI received after a time point of the nth subframe is an uplink grant received during a duration from a reception point of a most recent polling on uplink grant before the nth subframe to an (N-1) th subframe.

7. The method of claim 1, wherein the second DCI is a UE-specific DCI or a UE-common DCI.

8. The method of claim 1, wherein the second DCI comprises at least any one of a non-adaptive retransmission on/off field, a non-adaptive retransmission timing field, a Redundancy Version (RV) field, and an aperiodic Channel State Information (CSI) transmission request field.

9. The method of claim 1, wherein a Radio Network Temporary Identifier (RNTI) value related to detection of the second DCI is independently signaled.

10. The method of claim 1, wherein transmission-related parameters within a search space for the second DCI are predetermined.

11. The method of claim 1, wherein in the event that the UE receives both the second DCI for the same HARQ process ID and an uplink grant, a retransmission is performed in accordance with the uplink grant for the same HARQ process ID.

12. The method of claim 1, wherein, within the second DCI, each HARQ process ID configures a HARQ ACK transmission timing field.

13. The method of claim 1, wherein each HARQ process ID configures an acknowledgement/negative Acknowledgement Resource Indicator (ARI) field within the second DCI.

14. A communication device that receives acknowledgement/negative acknowledgement (ACK/NACK) information, comprising:

a Radio Frequency (RF) unit that transmits and receives a radio signal; and

a processor operatively connected to the RF unit,

wherein the processor is configured to:

receiving first Downlink Control Information (DCI) including an Uplink (UL) grant from a network,

transmitting uplink data to the network, an

Receiving second DCI for feedback on the uplink data from the network,

wherein the second DCI includes a Transmit Power Control (TPC) command for retransmission and ACK/NACK information scheduled by the second DCI,

wherein the ACK/NACK information relates to a plurality of hybrid automatic repeat request (HARQ) process Identifiers (IDs),

wherein the ACK/NACK information comprises a plurality of bits,

wherein each of the plurality of HARQ process IDs is related to a corresponding one of the plurality of bits in ascending order,

wherein a payload size of the second DCI is the same size as a payload size of the first DCI, and

wherein the second DCI is identified based on a flag in the second DCI.

15. A method of transmitting acknowledgement/negative acknowledgement (ACK/NACK) information in a wireless communication system, the method performed by a network comprising:

transmitting first Downlink Control Information (DCI) including an Uplink (UL) grant to a user equipment;

receiving uplink data from the UE; and

transmitting, to the UE, second DCI for feedback on the uplink data; and

wherein the second DCI includes a Transmit Power Control (TPC) command for retransmission and ACK/NACK information scheduled by the second DCI,

wherein the ACK/NACK information is related to a plurality of hybrid automatic repeat request (HARQ) process Identifiers (IDs),

wherein the ACK/NACK information comprises a plurality of bits,

wherein each of the plurality of HARQ process IDs is related to a corresponding one of the plurality of bits in ascending order,

wherein a payload size of the second DCI is the same size as a payload size of the first DCI, and

wherein the second DCI is identified based on a flag in the second DCI.

16. A communication device that transmits acknowledgement/negative acknowledgement (ACK/NACK) information, comprising:

a Radio Frequency (RF) unit that transmits and receives a radio signal; and

a processor operatively connected to the RF unit,

wherein the processor is configured to:

transmitting first Downlink Control Information (DCI) including an Uplink (UL) grant to a User Equipment (UE),

receiving uplink data from the UE, an

Transmitting second DCI for feedback on the uplink data to the UE,

wherein the second DCI includes a Transmit Power Control (TPC) command for retransmission and ACK/NACK information scheduled by the second DCI,

wherein the ACK/NACK information relates to a plurality of hybrid automatic repeat request (HARQ) process Identifiers (IDs),

wherein the ACK/NACK information comprises a plurality of bits,

wherein each of the plurality of HARQ process IDs is related to a corresponding one of the plurality of bits in ascending order,

wherein a payload size of the second DCI is the same size as a payload size of the first DCI, and

wherein the second DCI is identified based on a flag in the second DCI.

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